MOLECULAR MECHANISMS--ISCHEMIA/REPERFUSION BRAIN INJURY

分子机制——缺血/再灌注脑损伤

• 批准号: 2273283
• 负责人: GARY M FISKUM
• 金额: $ 28.27万
• 依托单位: GEORGE WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-05-01 至 1999-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2273283
• 关键词: Krebs' cycle; PC12 cells; bioenergetics; brain injury; brain metabolism; calcium flux; cellular pathology; cellular respiration; cerebral ischemia /hypoxia; dogs; enzyme activity; free radicals; heart arrest; lipid metabolism; mitochondria; neuroprotectants; oxidative stress; oxygen consumption; oxygen therapy; peroxides; reperfusion; resuscitation; tissue /cell culture

DESCRIPTION: (Adapted from investigator's abstract) Free radical- mediated damage to lipids and proteins, altered mitochondrial electron transport chain activities and abnormal patterns of tissue metabolism are strongly implicated in the pathophysiology of neurological morbidity caused by global cerebral ischemia and reperfusion. The overall objective of this project is to characterize the relationships between these factors and to relate them to the neurological impairment observed with animals subjected to a clinically relevant scenario consisting of cardiac arrest followed by 30 minutes to 24 hours of restoration of spontaneous circulation. The specific aims of these studies are to test the following hypotheses: (1) A short period of global ischemia causes immediate and reversible alterations in mitochondrial respiratory and Ca2+ uptake activities that are distinguishable from delayed, reperfusion-induced alterations. (2) Free radical damage due to cerebral ischemia/reperfusion adversely affects proteins as well as lipids present within mitochondria and other cellular compartments and membranes. (3) Mitochondrial membrane damage and enzyme inactivation result in immediate and delayed alterations in cerebral energy metabolism following cardiac arrest and ROSC. (4) Clinically-feasible manipulations of inspired and brain 02 concentrations alter the degree of molecular, subcellular, and metabolic injury, corresponding to differences in the extent of neurological injury observed following these different resuscitation protocols. Methods of approach to these aims will include measurements of 02 consumption, peroxide formation and Ca2+ uptake by isolated brain mitochondria and digitonin-permeabilized synaptoneurosomes and PC12 pheochromocytoma cells; determinations of lipid and protein oxidation, measurements of phospholipid and free fatty acid moieties and determinations of metabolic activities associated with glycolysis and the TCA cycle. Additional support for involvement of specific subcellular and metabolic alterations in the pathogenesis of ischemia/reperfusion brain injury will come from comparison of results obtained with different animal treatment protocols as well as with neurochemical measurements and histological testes. In vitro modeling of cellular and subcellular injury will also assist in the elucidation of cause and effect relationships. The significance of these studies is that they will provide unique molecular insight into the roles that altered bioenergetics and free-radical-metabolism play in brain injury associated with cardiac arrest and resuscitation as well as other forms of cerebral ischemia including stroke and trauma.

描述：（根据研究者的摘要进行了改编）自由基 - 介导对脂质和蛋白质的损害，线粒体电子改变 传输链活动和组织代谢的异常模式 与神经系统发病的病理生理非常重要 由全球脑缺血和再灌注引起。 总体 该项目的目的是表征 这些因素并将它们与观察到的神经系统障碍联系起来 动物受到临床相关的情况，包括 心脏骤停，然后进行30分钟至24小时的恢复 自发循环。 这些研究的具体目的是检验以下假设： （1）全球性缺血的短期导致立即和可逆的 线粒体呼吸道和Ca2+摄取活动的改变 可与延迟的，再灌注诱导的改变。 （2） 由于脑缺血/再灌注而造成的自由基损害不利 影响线粒体和其他线粒体中存在的蛋白质以及脂质 细胞室和膜。 （3）线粒体膜损伤 酶失活导致立即和延迟的改变 心脏骤停和ROSC后的脑能量代谢。 （4） 临床上启发和大脑的操纵02 浓度改变了分子，亚细胞和代谢的程度 损伤，对应于神经损伤程度的差异 遵循这些不同的复苏协议。 这些目标的方法方法将包括02的测量 孤立的大脑消耗，过氧化物形成和Ca2+摄取 线粒体和Digitonin-渗透性突触体和PC12 嗜铬细胞瘤细胞； 确定脂质和蛋白质氧化， 测量磷脂和游离脂肪酸部分以及 确定与糖酵解和糖酵解相关的代谢活性 TCA周期。 额外的支持以参与特定 亚细胞和代谢改变的发病机理 缺血/再灌注脑损伤将来自结果的比较 通过不同的动物治疗方案以及 神经化学测量和组织学睾丸。 体外建模 细胞和亚细胞损伤也将有助于阐明 因果关系。 这些研究的意义 是他们将对角色的独特洞察力提供独特的见解 在脑损伤中改变生物能学和自由基 - 生物代谢 与心脏骤停和复苏以及其他形式有关 脑缺血，包括中风和创伤。